masturbation vs pocket pool

masturbation

noun
  • Manual erotic stimulation of the genitals or other erotic regions, often to orgasm, either by oneself or a partner. 

  • A vain activity. 

pocket pool

noun
  • The act of manipulating one's genitalia through a trouser pocket; masturbation. 

  • A variation of the game of pool. 

How often have the words masturbation and pocket pool occurred in a corpus of books? (source: Google Ngram Viewer )